Against the backdrop of accelerating the construction of a maritime power and achieving sustained and stable development of the marine economy, scientifically evaluating the impact of the maritime power strategy on the total factor productivity of marine related enterprises can help improve the quality and efficiency of the marine related industrial structure. Based on data from marine related enterprises in listed companies from 2007 to 2022, this article uses a difference in differences model to quantitatively evaluate the total factor productivity level of marine related enterprises before and after the construction of a maritime power, and analyzes them from three aspects: regional heterogeneity, enterprise ownership heterogeneity, and enterprise financial debt ratio heterogeneity. The results showed that the construction of a maritime power has a significant positive effect on promoting the improvement of total factor productivity of China's maritime enterprises. Based on this, in order to promote the development of China's marine industry, the following suggestions are proposed: (1) Each region should formulate practical marine economic development strategies according to its own geographical location, resource endowment, and other conditions; (2) Strengthen the leading and exemplary role of state-owned enterprises; (3) Innovate financial service models to meet the unique financial needs of the marine industry.